9. Cooling water system
163
9.3.3 Fresh water pump disassembly
(1) Do not disassemble the fresh water pump. It is difficult to disassemble and, once
disassembled, even more difficult to reassemble. Replace the pump as an assembly in
the event of trouble.
(2) When removing the fresh water pump, replace the O-ring (inlet to cylinder).
(3) When the fresh water pump and pump body and/or fresh water pump and pump plate
are disassembled, retighten to the specified torque.
9.3.4 Fresh water pump inspection
(1) Bearing unit inspection
Rotate the impeller smoothly. If the rotation is not smooth or abnormal noise is head
due to excessive bearing play or contact with other parts, replace the pump as an
assembly
(2) Impeller inspection
Check the impeller blade, and replace if damaged or corroded or if the impeller blade is
worn due to contact with pump body.
(3) Check the holes in the cooling water and bypass lines, clean out any dirt or other
foreign matter and repair as necessary.
(4) Replace the pump as an assembly if there is excessive water leakage due to
mechanical seal or impeller seal wear or damage.
(5) Inspect the fresh water pump body, clean off scale and rust, and replace if corroded.
(6) Measure the outside clearance between the impeller and the pump body, by pushing
the impeller all the way towards the body, and inserting a thickness gauge diagonally
between the impeller and the body.
Measure the side clearance between the impeller and the plate by placing a straight-
edge against the end of the pump body and inserting a thickness gauge between the
impeller and the straight-edge.
Measuring outside clearance between impeller and
pump body.
Tightening torque for pump
setting bolts
392-785 N•cm
(40-80 kgf•cm)
mm
Standard
Limit
Outside clearance between
impeller and body
0.3-1.1
1.5
Thickness gauge
Summary of Contents for 3YM20
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